If one fluid is rated at 250 SSU, what can be said about its viscosity compared to a fluid rated at 150 SSU?

The correct choice indicates that a fluid rated at 250 SSU has higher viscosity than a fluid rated at 150 SSU. The Saybolt Seconds Universal (SSU) is a measurement used to determine the viscosity of liquids, where a higher SSU value indicates greater resistance to flow.

Viscosity is a measure of a fluid's thickness or internal friction, affecting how easily it flows. Therefore, when comparing two fluids using this scale, the one with the higher SSU rating will always be the more viscous fluid. Since 250 SSU is greater than 150 SSU, it directly follows that the fluid with 250 SSU is thicker and has a higher viscosity compared to the fluid with 150 SSU. Understanding this relationship between SSU values and viscosity is fundamental in hydraulics and fluid mechanics.